The MrBestCloud Leak Started Weeks Ago. Part 2 Just Hit 4.9 Million.

HEROIC analysts identified MRBESTCLOUD_Part002, a massive stealer log uploaded by a Telegram user on April 16, 2026. As the "Part002" label suggests, this is the second installment in an ongoing series, and it alone contains 4,882,993 records, nearly 4.9 million email addresses paired with plaintext passwords and the exact URLs those credentials unlock. The fact that this operation is releasing numbered parts shows it has a large, continuing supply of stolen data rather than a single one-time dump.

Why the MrBestCloud Leak Series Is Dangerous

A single part of this leak already outnumbers the population of many mid-sized cities, and every one of those 4.9 million records pairs a working password with the exact site it belongs to. That kind of specificity removes nearly all the guesswork attackers normally face. With more parts likely to follow, the total number of exposed accounts tied to this operation could climb well beyond what has already surfaced, making it one of the more concerning stealer log campaigns HEROIC has tracked this year.

What Was Exposed in MRBESTCLOUD_Part002

• Email addresses tied to real user accounts
• Plaintext passwords stored without encryption
• URLs identifying the exact site or service each login unlocks

Why This Matters for the 4.9 Million Records in Part 2 Alone

At this scale, the fallout reaches far beyond any single service. Attackers feed leaked email and password pairs into automated credential stuffing tools that test the same login across banking sites, email providers, and online retailers within seconds. Anyone who reused a password from this dump elsewhere has effectively exposed that account too. Multiply this by millions of records, and the result is a wave of account takeovers, fraudulent transactions, and identity theft cases that can take months to sort out.

How a Multi-Part Stealer Log Operation Like MrBestCloud Builds Its Files

Info-stealing malware infects devices through phishing links, cracked software, or malicious downloads, then quietly copies saved browser credentials before packaging them into structured log files. Operations that release numbered parts, like MRBESTCLOUD_Part002, are typically managing a steady pipeline of newly infected machines, batching the stolen data into digestable chunks rather then releasing everything at once. This approach lets the group build a reputation and keep buyers or downloaders coming back for each new release.

Check If You Are Affected by the MrBestCloud Leak

With millions of records already exposed, and possibly more parts on the way, checking your exposure now is essential. HEROIC's free breach scanner searches your email against a database of more than 400 billion leaked records, including this MRBESTCLOUD_Part002 file, so you can find out your risk in seconds. If you get a match, change that password immediately, avoid reusing it elsewhere, and enable two-factor authentication. Scan now before the next part of this leak surfaces.